RunRyder RC
WATCH
 1 page 213 views POST REPLY
HomeScaleAircraftHelicopterScale Model RC Helicopters › TT Hind T-ex 600 help.
08-06-2018 06:39 PM  12 days agoPost 1
SJN

rrApprentice

Denmark EKCH

My Posts: All  Forum  Topic

Hi Guys. I just installed a t-rex 600 CF in my Thunder Tiger hind fuselage, but I must admit Im not an expert in electric heli stuff. I think I overloaded the ESC, by running a too low headspeed, and pulling too much pitch. I hovered it for about 30 seconds, then it lost power, and the ESC went up in flames....fire shot out of the scale exhausts, and I ran over to the heli, and yanked the battery out of it Luckily, it had de-soldered all of the lead off of the esc, so the battery was not shorted. Luckily, the esc was mounted pretty good away from most stuff, and the fuselage is rather large, so there is actually no dmamge to the fuselage. Only black soot that can be wiped off. I bought the T-rex second hand, and it seems to have been through a few hands. the head is metal, but the rest is a stock old CF version. It has a BL600XL 1650KV motor on it and a 10 tooh pinion, and used a BL100G ESC. I had it in govenor mode, and 85% flat throttle curve, but the headspeed seemed quite low, and It as hovering at 3/4 stick Pitch curve at -4, 6 mid, and 12 full pitch.
I dont understand why the RPM was so low.
I should have flown the heli before installing it in the fusealge. Mayb the ESC or motor was bad ? I got it realy cheap. I have removed the motor, and the bearings dont sound great.....but not catastrophic bad. You guys think I should get a new YEP ESC, and try the motor again, or should I buy a new motor too ? Is the 10 tooth pinion an ok match for the 1650 kv motor, or is it a bad match for a scale heli that weighs 5kg?

Sonnich Johannesen

PM  EMAIL  GALLERY  Attn:RR  Quote
08-06-2018 07:30 PM  12 days agoPost 2
Grimracer

rrVeteran

Eau Claire WI

My Posts: All  Forum  Topic

How many S?

Grim

Michael J Zaborowski

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
08-06-2018 07:31 PM  12 days agoPost 3
SJN

rrApprentice

Denmark EKCH

My Posts: All  Forum  Topic

sorry....the most important thing :-) 6S 5800 30C

Sonnich Johannesen

PM  EMAIL  GALLERY  Attn:RR  Quote
08-06-2018 08:06 PM  12 days agoPost 4
Sidneyw

rrApprentice

Huntersville, NC

My Posts: All  Forum  Topic

I have not used Align ESC in governor mode; but one thing for sure, did you calibrate the ESC min/max throttle range before you run governor mode?

PM  EMAIL  GALLERY  Attn:RR  Quote
08-06-2018 08:10 PM  12 days agoPost 5
SJN

rrApprentice

Denmark EKCH

My Posts: All  Forum  Topic

I tried......but probably not hard enough. I connected it with full throttle, and took it down to zero, but Im not sure that it calibrated properly......should have read up a bit more on it. So it might not have been calibrated for my radio. I have ordered a YEP 120 ESC, and a Turnigy 1220KV motor, and a 14 tooth pinion. That setup runs great on my T-rex ESP.....which will go into a Funkey Airwolf soon. But I think you are right about the throttle calibration......that could also explain the low head speed.

Sonnich Johannesen

PM  EMAIL  GALLERY  Attn:RR  Quote
08-07-2018 04:46 AM  11 days agoPost 6
coptercptn

rrElite Veteran

Mesa AZ. USA

My Posts: All  Forum  Topic

It looks like you are on the right track w/1220 motor. It appears that you overloaded the motor/esc. If your new esc has “data logging it would be nice to see what loads are being placed on the drive...?

Home of the "Sea Cobra".....

PM  EMAIL  GALLERY  Attn:RR  Quote
08-07-2018 09:07 AM  11 days agoPost 7
SJN

rrApprentice

Denmark EKCH

My Posts: All  Forum  Topic

No, the YEP ESC is not that advanced :-)
But it works great, and is easy to program with the program card.

I was also taking it easy on the headspeeds, and checking for vibration in the fuselage....and it was doing great. I just should not have lifted off at the low head speed.......you learn something new every day :-)

Ordered this ESC: https://hobbyking.com/en_us/yep-120...table-sbec.html

And this motor: https://hobbyking.com/en_us/turnigy...pter-motor.html

Sonnich Johannesen

PM  EMAIL  GALLERY  Attn:RR  Quote
08-07-2018 09:39 AM  11 days agoPost 8
Andy01

rrApprentice

Brisbane, Australia

My Posts: All  Forum  Topic

Well, I have no idea how the ESC governor works, but based on the data (and assuming a 170T Mod 0.7 main gear), the headspeed should not have been too low.

This may, of course be an incorrect assumption because I have never seen a 10T Mod 0.7 pinion, even for a 5mm motor shaft, so you may have a different gearing set, but I did not see a mention of the main gear size.

RPM = 1650kV x 22.2V x 0.9 (efficiency) x 10T / 170T = 1940rpm, and throttling to 85% gives 1650rpm, which is actually quite high for a scale 600 sized heli - I run my 500 sized UH-1N at 1700rpm.

With scale, there is no need for lots of power, or big ESCs, but using the 1220kV and the same gearing,

RPM = 1220 x 22.2 x 0.9 x 14T / 170T = 2007rpm at 100% throttle towards the end of the flight.

Now, I would suggest that this is almost certainly too fast, so I would suggest looking for a smaller pinion. I would think that you would want to run at about 1550rpm as a governed speed, and you would want to run the governor at 90-95%, so you would be aiming for a calculated headspeed (using the above formula) of about 1650-1700rpm (to get you down to a governed speed around the 1550rpm mark.

This means that you probably want either an 11T or 12T pinion - again assuming a Mod 0.7 170T main gear. If it is different you can use the formula to work it out for yourself.

Colin

Vario Long Ranger 700e
Seahawk 600
UH-1N 500
Baumann EC-145 800+ (coming soon )

PM  EMAIL  GALLERY  Attn:RR  Quote
08-07-2018 01:51 PM  11 days agoPost 9
co_rotorhead

rrVeteran

Centennial, CO, USA

My Posts: All  Forum  Topic

SJN
I should have flown the heli before installing it in the fuselage.
In this case, this was a hard lesson to learn, but it really is one of the most important steps in a scale build. I hope your Hind is back in the air soon.

PM  EMAIL  GALLERY  Attn:RR  Quote
08-08-2018 08:50 PM  10 days agoPost 10
steph

rrKey Veteran

Hampshire England

My Posts: All  Forum  Topic

I have the same fuz initially I was flying it on 6s setup but the flight times were poor so I changes the motor and esc for a 12s setup now I can fly for 10 min plus and everything is cool to the touch

when I first got the hind it had raptor 50 mech's I changed them to ccpm and fitted a 5 blade head with spin A symmetrical blades
this setup was good but I was never happy with the three belt setup for the tail so I shoe horned a trex 700 into the fuz now she fly's like she is on rails
my batts are multistar 5200 with a castle creations esc and a scorpion motor 330 kv

Here is a link to my hind flying on 12s with raptor mech's

Watch at YouTube

The world is round you can run but you will always end up where you started from

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 1 page 213 views POST REPLY
HomeScaleAircraftHelicopterScale Model RC Helicopters › TT Hind T-ex 600 help.
 Print TOPIC  Make Suggestion 

 4  Topic Subscribe

Saturday, August 18 - 11:37 pm - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online